Stilbene optical brighteners and compositions brightened therewith

ABSTRACT

Benzofurans, benzothiophenes, indoles, naphthofurans and benzofuranobenzofurans which are substituted by 4-vinyl-phenyl groups wherein the 2-position of the vinyl is substituted by a monovalent aromatic radical having one to three aromatic rings are optical brightening agents useful for whitening and brightening natural and synthetic fibers, papers, resins and the like. The compounds are conveniently prepared by interacting benzofurans, benzothiophenes, indoles, naphthofurans or benzofuranobenzofurans which are substituted by a p-tolyl group, with an aromatic aldehyde or preferably the anil derivative thereof.

This application is a continuation-in-part of our prior copending U.S.Pat. application Ser. No. 118,076, filed Feb. 23, 1971, now U.S. Pat.No. 3,781,279.

This invention relates to compositions of matter classified in the artof chemistry as substituted stilbenes, to processes for theirpreparation, and to intermediates for the same.

The compounds of this invention are useful as fluorescent whitening andbrightening agents for treatment of threads, sheets, films, filaments,textile fabrics, castings, moldings, and the like as well as in themanufacture of textiles, paper, varnishes, inks, coatings and plastics.These compounds are particularly valuable because of their strong blueshade of fluorescence and their excellent stability to light,chlorinetype bleaches and elevated temperatures.

In the first of its compositions of matter aspects, the invention soughtto be patented resides in the novel chemical compounds of Formula I##SPC1##

wherein X is a member of the class consisting of O, S, and N-R, whereinR is H, alkyl having one to six carbon atoms or alkenyl having 2 to 6carbon atoms; R₁ is hydrogen, alkyl having one to six carbon atoms,alkoxy having 1 to 6 carbon atoms or halo; R₂ and R₃ are the same ordifferent and are members of the class consisting of H, alkyl having 1to 6 carbon atoms, alkoxy having 1 to 6 carbon atoms, halo, dialkylaminowherein each alkyl has one to six carbon atoms, alkanoylamino having 1to 6 carbon atoms, phenyl, or phenyl substituted by alkyl having 1 to 6carbon atoms, halo, alkoxy having 1 to 6 carbon atoms, or alkanoylaminohaving 1 to 6 carbon atoms; and A is a monovalent aromatic radicalhaving one to three aromatic rings.

In a second composition of matter aspect, the invention sought to bepatented resides in the novel chemical compounds of Formula II ##SPC2##

wherein R' is selected from the class consisting of H, alkyl having 1 to6 carbon atoms, alkoxy having 1 to 6 carbon atoms, halo, dialkylaminowherein each alkyl group has one to six carbon atoms, alkanoylaminohaving 1 to 6 carbon atoms, phenyl or phenyl substituted by alkyl havingone to six carbon atoms, halo, alkoxy having 1 to 6 carbon atoms, oralkanoylamino having 1 to 6 carbon atoms; R₁ has the same significanceas in Formula I; and Z is selected from the class consisting of naphtho(that is, 1,2-naphtho, 2,1-naphtho, or 2,3-naphtho) and dibenzofurano(that is, 1,2-dibenzofurano, 2,1-dibenzofurano or 2,3-dibenzofurano).

In a third composition of matter aspect, the invention sought to bepatented resides in the novel compounds of Formula III ##SPC3##

wherein R₁, R₂, R₃, and X each have the same significance as in FormulaI with the provision that when X represents an oxygen atom at least oneof R₁, R₂ and R₃ is other than H.

In a fourth composition of matter aspect, the invention sought to bepatented resides in the novel compounds of Formula IV ##SPC4##

wherein R₁ has the same significance as in Formulas I, II, and III, andZ has the same significance as in Formula II.

In the first of its process aspects, the invention sought to be patentedresides in the method which comprises interacting a compound of FormulaIII with an aldehyde, A-CHO, or preferably the anil derivative thereof,A--CH=N-C₆ H₅, wherein A has the same significance as in Formula I toyield a substituted stilbene compound of Formula I.

In a second process aspect, the invention sought to be patented residesin the method which comprises interacting a compound of Formula IV witha benzaldehyde compound, ##SPC5##

or preferably, the anil derivative thereof of the Formula ##SPC6##

wherein R' has the same significance as in Formula II, to yield asubstituted stilbene compound of Formula II.

When R₁, R₂, R₃, and R', in the formulas herein are halo, there areincluded chloro, fluoro, bromo, and iodo. The preferred halo substituentis chloro because of the relatively low cost and ease of preparation ofthe required intermediates. However, the other above-named halosubstituents are also satisfactory.

When R, R₁, R₂, R₃, and R' in the formulas herein are alkyl having oneto six carbon atoms, there are included, for example, methyl, ethyl,propyl, isopropyl, butyl, sec.butyl, tert.-butyl, isobutyl, amyl, hexyl,2,3-dimethylbutyl, and the like.

When R₁, R₂, R₃, and R' in the formulas herein are alkoxy having one tosix carbon atoms, there are included, for example, methoxy, ethoxy,propoxy, isopropoxy, butoxy, isobutoxy, tert.-butoxy, amyloxy, hexyloxy,and the like.

When R₂, R₃, and R' in the formulas herein are dialkylamino, each alkylgroup having from 1 to 6 carbon atoms, there are included for example,dimethylamino, diethylamino, dipropylamino, dibutylamino, dipentylamino,dihexylamino, methylethylamino, N-methyl-N-butylamino, and the like. Forthe purposes of this invention the common amine radicals wherein the twoalkyl groups are joined to form a ring, for example, pyrrolidino,piperidino, morpholino, thiomorpholino, and N-methylpiperazino, areequivalent to the dialkylamino compounds claimed herein.

When R₂, R₃, and R' are in the formulas herein are alkanoylamino havingone to six carbon atoms, there are included, for example, formamido,acetamido, propionamido, butyramido, isobutyramido, valeramido,isovaleramido, caproamido, and the like.

When R in Formulas I and III above is alkenyl having two to six carbonatoms, there are included, for example, alkyl, 2-methyl-2-propenyl,2-butenyl, 4-pentenyl, 3-methyl-2-butenyl, 2-hexenyl, 3-hexenyl,1-methyl-2-propenyl, 1,3-dimethyl-2-butenyl, and the like.

When R₂, R₃, and R' in the formulas herein are substituted phenyl, thereare included, for example, p-tolyl, o-tolyl, m-tolyl, p-ethylphenyl,p-acetamidophenyl, o-acetamidophenyl, m-hexanoylaminophenyl,p-chlorophenyl, o-chlorophenyl, m-bromophenyl, o-methoxyphenyl,p-ethoxyphenyl, 2,4-dimethoxyphenyl, 3,4-dichlorophenyl,2,4-dimethylphenyl, and the like.

In Formula I, A represents a monovalent aromatic radical having one tothree aromatic rings. That is, A is a monocyclic, bicyclic, or tricyclicradical having from two to seven conjugated double bonds within the ringsystem. The rings may be fused as in, for example, the naphthyl radical,or they may be joined in series, as in, for example, the biphenylylradical. Moreover, the rings may be carbocyclic or heterocyclic.Examples of aromatic rings represented by A in Formula I are phenyl,2-naphthyl, 1-naphthyl, p-methoxyphenyl, p-chlorophenyl, o-chlorophenyl,4-biphenylyl, 9-phenanthrenyl, 9-anthryl, 2-benzofuranyl, 2-indolyl,2-benzothiophenyl, 6-methoxy-2-naphthyl, 2-butoxy-1-naphthyl,5-bromo-1-naphthyl, 3-coumarinyl, 2-indenyl, 2-quinolinyl, 3-quinolinyl,2-pyridyl, 3-pyridyl, 4-pyridyl, 2-furanyl, 2-benzoxazolyl,2-benzothiazolyl, 2-naphtho[2,1-b]furanyl, 2-naphtho[1,2-b]furanyl, andthe like.

The compounds of Formulas I and II are useful as fluorescent whiteningand brightening agents in treating white and colored fabrics in order toneutralize the yellowness which develops with age in white textiles andto enhance the brilliance of colored textiles. In such utilization thehigh resistance of these compounds to chlorine bleaches and to light aredistinct advantages. Another valuable advantage offered by thesecompounds is their unusual stability at high temperatures, which permitstheir use in high melting polymers. They are effectively employed atconcentrations in the range of 0.005 to 0.5 percent by weight of thematerial to be brightened.

The compounds of Formulas III and IV are useful as intermediates for thepreparation of the novel fluorescent whitening and brightening agents ofFormulas I and II. Moreover, certain of the compounds of Formula IV, forexample, 2-(p-tolyl)naphtho[1,2-b]furan, 2-(p-tolyl)naphtho[2,1-b]furanand 2-(p-tolyl)benzothiophene, are also useful as antifertility agentsin mammalian animals. In such utilization, tests have shown that,following administration of these compounds to pregnant rats at a dosagelevel of 100 mg./kg., development of the fetus is terminated, and thefetus is resorbed in the uterus with no noticeable deleterious effectsto the mother.

The manner and process of making and using the invention, and the bestmode contemplated by the inventor of carrying out the invention, willnow be described so as to enable any person skilled in the art to whichit pertains to make and use the same.

In general, the compounds of Formulas I and II of this invention areconveniently obtained by interacting an aromatic carboxaldehyde (forexample, A-CHO, wherein A has the same significance as in Formula I) orpreferably the anil derivative of such aromatic carboxaldehyde, i.e.,A--CH=N-C₆ H₅, with a compound having the structure ##SPC7##

for making the compounds of Formula I, and the structure ##SPC8##

for making the compounds of Formula II. The condensation can usually becarried out at rather low temperatures (0-55°C.) in a suitable solventand in 0°-presence of a strongly alkaline reagent. Under theseconditions, the reaction is generally complete in approximately 1/2 tothree hours.

Suitable solvents are those highly polar solvents which are free ofacidic hydrogen or other atoms or radicals which may react with stronglyalkaline reagents. Examples of suitable solvents includedimethylformamide, dimethylacetamide, diethylformamide,hexamethylphosphoramide, N-formylpiperidine, and sulfolane.

The strongly alkaline reagents suitable for the condensation include thealkali metal salts of tertiary aliphatic alcohols, alkali metalhydroxides, alkali metal amides and alkali metal hydrides. However, thenature of the alkaline reagent (other than its basicity) is not criticalto the invention, and any alkaline compound of comparable basicity underthe reaction conditions can be employed herein.

Because of the reactive nature of the alkaline reagent, it is preferableto conduct this condensation reaction in a manner which will excludeatmospheric moisture and carbon dioxide. Accordingly, for such purposean atmosphere of dry nitrogen or other inert gas over the reactionmedium is provided.

The intermediate compounds of Formulas III and IV wherein X is O or Sare conveniently prepared by cyclizing an appropriately-substituted4-methylphenacyl ether or thioether of Formula V and Formula VI,respectively: ##SPC9##

wherein R₁, R₂, R₃, and Z have the same meanings as defined above and Xis O or S. The cyclization is carried out by heating the phenacyl ethercompound in a dehydrating medium, for example, sulfuric acid orpreferably polyphosphoric acid, at a temperature in the range 75°-110°C.Cyclization is usually complete in from one to six hours under theseconditions. The product of cyclization is then rearranged to the desiredintermediates of Formulas III and IV by continued heating at 130°-150°C.in the same reaction medium, as disclosed in the prior art, J. Chem.Soc., 1958, 822.

The requisite 4-methylphenacyl ether intermediates are generally knowncompounds prepared according to procedure well known to those skilled inthe art.

When X in the above formulas represents >N-R, that is, in the case ofsubstituted indoles, the intermediate compounds are convenientlyprepared by alkylation of the known compound, 2-(p-tolyl)indole, inaccordance with alkylation procedures well known in the art, forexample, by interacting 2-(p-tolyl)indole with an alkyl or alkenylhalide in the presence of an alkaline reagent. In this way2-(p-tolyl)indole can be interacted with, for example, methyl iodide,ethyl bromide, n-propyl bromide, n-butyl bromide, isobutyl bromide,n-hexyl chloride, allyl chloride, 1-bromo-2-pentene, and the like toproduce, respectively, 1-methyl-2-(p-tolyl)indole,1-ethyl-2-(p-tolyl)indole, 1-propyl-2-(p-tolyl)indole,1-butyl-2-(p-tolyl)indole, 1-isobutyl-2-(p-tolyl)indole,1(n-hexyl)-2-(p-tolyl)indole, 1-allyl-2-(p-tolyl)indole,1-(2-pentenyl)-2-(p-tolyl)indole, and the like.

Alternatively, the indole intermediates can be prepared in a mannersimilar to that employed in preparing the other intermediate2-(p-tolyl)-substituted compounds disclosed herein, namely, by cyclizingthe appropriately-substituted N-(4-methylphenacyl)aniline, ##SPC10##

(wherein R is as defined above) by heating said compound with a Lewisacid, for example, zinc chloride, at temperatures of 125°-250°C. inaccordance with procedures known to the art.

A preferred mode of utilizing the compounds of Formulas I and II is toincorporate them into melts of synthetic plastic material for spinningsynthetic fibers or for casting or molding plastics in an appropriateconcentration, for example 0.01 to 0.1 percent by weight of the melt.

A further method of utilizing the compounds of Formulas I and II is toimpregnate textile fabrics comprising synthetic fibers, for examplepolyester (poly[terephthalic acid ethylene glycol ester]) or nylon, withan aqueous dispersion of the compound at temperatures below about 75°C.,for example, at room temperature and then to subject the treated fabricto a dry heat treatment at a temperature above 100°C. The fabric mayadvantageously be dried at temperatures in the range 60°-100°C. prior tothe heat treatment, which is preferably carried out at temperatures inthe range 125°-250°C. Said heat treatment may be accomplished by any ofseveral known methods, for example, by heating in a drying chamber, byironing the fabric, or by treating it with dry superheated steam.

The structures of the compounds of this invention were established bythe modes of synthesis, by elementary analysis, and by ultraviolet,infrared, and nuclear magnetic resonance spectra. The course of thereactions and homogeneity of the products were ascertained by thin layerchromatography.

The invention is illustrated by the following examples without, however,being limited thereto. Melting points are uncorrected except whereotherwise indicated.

EXAMPLE 1

a. A mixture containing 72.6 g. (0.3 mole) ofω-phenylmercapto-p-methylacetophenone and 325 ml. of polyphosphoric acidwas heated to 180°-190°C. for 3 hours. The progress of the reaction wasfollowed by ultraviolet spectroscopy, and the completion of the reactionwas shown by the disappearance of the curve characteristics of thestarting material and the appearance of a new maximum at 358 nm. Thereaction mixture was allowed to cool and was then poured into water. Theresulting mixture was collected on a filter and was purified bytriturating with dilute sodium hydroxide solution. The resultingproduct, 2-(p-tolyl)benzothiophene, was collected on a filter, washedfree of alkali with water and recrystallized from 2-ethoxyethanol. Theresulting pure 2-(p-tolyl)benzothiophene melted at 169°-171°C.

b. A solution containing 6.72 g. (0.03 mole) of2-(p-tolyl)-benzothiophene and 5.43 g. (0.03 mole) of benzalaniline in200 ml. of freshly distilled, dry dimethylformamide was flushed withnitrogen for 15 minutes, and 10.08 g. (0.09 mole) of potassiumtert.-butoxide was then added with stirring. The color of the reactionmixture progressively changed from red-brown to dark violet to violetand the temperature spontaneously rose from 23° to 32°C. Analysis of analiquot by ultraviolet spectroscopy showed that the reaction wascompleted after one hour of stirring. The reaction mixture was added toexcess water, the resulting precipitate was collected on a filter, andthe filter cake was washed with water. The precipitate was then slurriedin hot dimethylformamide and made acidic with 10% aqueous hydrochloricacid. This mixture was then diluted with water, and the precipitate wascollected on a filter. The resulting product,2-(4-stilbenyl)benzothiophene was purified by recrystallization fromxylene and by sublimation. The pure 2-(4-stilbenyl)benzothiophene thusobtained melted at 295.5°-296°C. The wavelength of maximum excitation ofthis compound was 359 nm., and the wavelength of maximum emission was412 nm.

EXAMPLE 2

Proceeding in a manner similar to that in example 1b above,2-(p-tolyl)benzothiophene (4.48 g.; 0.02 mole) was interacted with 4.22g. (0.02 mole) of p-methoxybenzalaniline in the presence of 6.72 g. ofpotassium tert.-butoxide in 150 ml. of dimethylformamide. Recrystallizedfrom dichlorobenzene, the resulting2-[4-(p-methoxy)stilbenyl]benzothiophene melted at 307°-308°C. withoutproducing a clear melt. The wavelength of maximum excitation of thiscompound was 369 nm., and the wavelength of maximum emission was 432 nm.

EXAMPLE 3

Proceeding in a manner similar to that used in Example 1b,2-(p-tolyl)benzofuran (4.16 g.; 0.02 mole) was interacted with 4.22 g.(0.02 mole) of p-methoxybenzalaniline in the presence of 6.72 g. (0.06mole) of potassium tert.butoxide in 150 ml. of dimethylformamide.Recrystallized from dichlorobenzene, the2-[4-(p-methoxy)stilbenyl]benzofuran thus obtained melted at 283°-285°C.The wavelength of maximum excitation of this compound was 369 nm., andthe wavelength of maximum emission was 425 nm.

EXAMPLE 4

Proceeding in a manner similar to that used in Example 3 except thatbenzalaniline was used in place of p-methoxybenzalaniline there wasobtained 2-(4-stilbenyl)benzofuran, which, when recrystallized fromxylene, melted at 269°-269.5°C. The wavelength of maximum excitation ofthis compound was 361 nm., and the wavelength of maximum emission was413 nm.

EXAMPLE 5

When 2-(p-tolyl)benzofuran was condensed with 2-naphthalanilineaccording to the procedure described in Example 1b there was obtained2-{4-[2-(naphthyl)vinyl]phenyl}benzofuran which melted at 282°-283° C.following recrystallization from dichlorobenzene. The wavelength ofmaximum excitation of this compound was 369 nm., and the wavelength ofmaximum emission was 424 nm.

EXAMPLE 6

Proceeding in a manner similar to that used in Example 3 except that4-chlorobenzalaniline is used instead of 4-methoxybenzalaniline therewas obtained 2-[4-(4'-chlorostilbenyl)]benzofuran which melted at293°-295° C. when recrystallized from dichlorobenzene. The wavelength ofmaximum emission was 420 nm., and the wavelength of maximum excitationwas 365 nm.

EXAMPLE 7

Proceeding in a manner similar to that used in Example 5 except that1-naphthalaniline was used in place of 2-naphthalaniline there wasobtained 2-{4-[2-(1-naphthyl)-vinyl]phenyl}benzofuran melting at154°-155° C. when recrystallized from 2-ethoxyethanol. The wavelength ofmaximum emission of this compound was 439 nm., and the wavelength ofmaximum excitation was 375 nm.

EXAMPLE 8

Proceeding in a manner similar to that used in Example 3, 3.10 g. (0.015mole) of 2-(p-tolyl)benzofuran was interacted with 3.85 g. of4-phenylbenzalaniline in the presence of 5.0 g. (0.054 mole) ofpotassium tert.-butoxide in 150 ml. of dimethylformamide. Recrystallizedfrom dichlorobenzene and washed with methanol, the2-(4'-phenyl-4-stilbenyl)benzofuran thus obtained remained unmelted at350° C. The wavelength of maximum excitation of this compound was 371nm., and the wavelength of maximum emission was 432 nm.

EXAMPLE 9

Following the procedure outlined in Example 3 except that9-phenanthrenecarboxaldehyde-N-phenylimine was used in place ofp-methoxybenzalaniline, there was obtained2-{4-[2-(9-phenanthryl)vinyl]phenyl}benzofuran. Recrystallized fromtoluene, this compound melted at 216°-218° C. The wavelength of maximumexcitation of this compound was 373 nm., and the wavelength of maximumemission was 447 nm.

EXAMPLE 10

a. Following the procedure given in Example 1aω-(β-naphthoxy)-4-methylacetophenone (27.6 g.; 0.1 mole) was heated with250 ml. of polyphosphoric acid and 25 ml. of methanesulfonic acid at135°-140° C. for eight hours. The reaction mixture was allowed to cooland was then poured into excess water. The resulting precipitate wascollected, washed with 10% sodium hydroxide solution, and then washedfree of alkali. Crystallized from ethylene glycol, the resulting2-(p-tolyl)-naphtho-[2,1-b]furan melted at 141°-142° C.

b. Following the procedure given in Example 1b2-(p-tolyl)-naphtho-[2,1-b]furan (4.3 g.; 0.016 mole) was interactedwith 3.1 g. (0.016 mole) of benzalaniline to produce2-(4-stilbenyl)-naphtho-[2,1-b]furan, which was purified byrecrystallization from xylene. Pure 2-(4-stilbenyl)naphtho[2,1-b]furanthus obtained melted at 248°-250° C. The wavelength of maximumexcitation of this compound was 377 nm., and the wavelength of maximumemission was 435.

EXAMPLE 11

a. Following the procedure given in Example 1aω-(α-naphthoxy)-4-methylacetophenone was heated with polyphosphoric acidto produce 2-(p-tolyl)-naphtho-[1,2-b]furan, which when crystallizedfrom ethylene glycol, melted at 97°-100° C.

b. Following the procedure given in Example 1b the above-named2-(p-tolyl)-naphtho-[1,2-b]furan was interacted with an equimolarquantity of benzalaniline to produce 2-(4-stilbenyl)naphtho[1,2-b]furanwhich, when crystallized from xylene and further purified bysublimation, melted at 228°-228.5° C. The wavelength of maximumexcitation of this compound was 370 nm., and the wavelength of maximumemission was 426.

EXAMPLE 12

Following the procedure given in Example 1b2-(p-tolyl)-6-methoxybenzofuran was interacted with an equimolarquantity of benzalaniline to produce2-(4-stilbenyl)-6-methoxybenzofuran, which, when recrystallized fromtoluene, melted at 223.5°-225.5° C. The wavelength of maximum excitationof this compound was 371 nm., and the wavelength of maximum emission was446 nm.

EXAMPLE 13

a. A mixture of 85 g. (0.5 mole) of p-phenylphenol, 84.25 g. (0.5 mole)of p-methylphenacyl chloride, 76.0 g. (0.55 mole) of potassium carbonate3.75 g. of potassium iodide and 350 ml. of acetone were refluxed withstirring for eight hours. The reaction mixture was allowed to cool andwas poured into a large excess of cold water. The precipitate wascollected and washed free of alkali with water. Followingrecrystallization from ethyl alcohol the resultingω-(4-biphenyloxy)-p-methylacetophenone melted at 101°-102.5° C.

b. Following the procedure given in Example 1a, the above-namedω-(p-biphenyloxy)-4-methylacetophenone was heated with polyphosphoricacid to give 5-phenyl-2-(p-tolyl)benzofuran, which, followingrecrystallization from 2-ethoxyethanol, melted at 156°-158° C.

c. Following the procedure given in Example 1b, the above-named5-phenyl-2-(p-tolyl)benzofuran was interacted with an equimolar quantityof β-naphthalaniline to give 5-phenyl-2-{4-[2-(2-naphthyl)vinyl]phenyl}benzofuran. Recrystallized from dichlorobenzene, thisproduct melted at 287°-288° C. The wavelength of maximum excitation ofthis compound was 374 nm., and the wavelength of maximum emission was427 nm.

EXAMPLE 14

When the procedure of Example 13c was repeated using4-phenylbenzalaniline in place of B-naphthalaniline there was obtained5-phenyl-2-{4-[2-(4-biphenylyl)vinyl]phenyl}benzofuran which, whenrecrystallized from dichlorobenzene, melted at 356°-358° C. Thewavelength of maximum excitation of this compound was 377 nm., and thewavelength of maximum emission was 434 nm.

EXAMPLE 15

a. Following the procedure given in Example 1aω-(p-chlorophenoxy)-p-methylacetophenone was heated with polyphosphoricacid to give 5-chloro-2-(p-tolyl)benzofuran which, when crystallizedfrom 2-ethoxyethanol melted at 183°-186° C.

b. When 5-chloro-2-(p-tolyl)benzofuran was condensed with4-phenylbenzalaniline as in Example 14 there was obtained5-chloro-2-{4-[2-(4-biphenylyl)vinyl]phenyl}benzofuran. Whenrecrystallized from dichlorobenzene this product remained unmelted at350° C. The wavelength or maximum excitation of this compound was 376nm., and the wavelength of maximum emission was 431 nm.

EXAMPLE 16

a. Following the procedure given in Example 13a 2,4-dichlorophenol wasinteracted with an equimolar quantity of 4-methylphenacyl chloride inthe presence of potassium carbonate to givew-(2,4-dichlorophenoxy)-p-methylacetophenone. Recrystallized from2-ethoxyethanol, this product melted at 96.5°-98.5° C.

b. Following the procedure given in Example 1a the above-namedω-(2,4-dichlorophenoxy)-p-methylacetophenone was heated withpolyphosphoric acid to give 5,7-dichloro-2-(p-tolyl)benzofuran which,following recrystallization from ethyl ether of ethylene glycol meltedat 116°-118° C.

c. Following the procedure given in Example 1b equimolar quantities ofthe above named 5,7-dichloro-2-(p-tolyl)benzofuran and4-phenylbenzalaniline were interacted in the presence of potassiumtert.-butoxide to give5,7-dichloro2-{4-[2-(4-biphenylyl)vinyl]phenyl}benzofuran which,following recrystallization from chlorobenzene, melted at 258°-260° C.The wavelength of maximum excitation of this compound was 375 nm., andthe wavelength of maximum emission was 431 nm.

EXAMPLE 17

When 5-chloro-2-(p-tolyl)benzofuran (Example 15) was condensed with anequimolar quantity of p-chlorobenzalaniline according to the method of1b, there was obtained 5-chloro-2-(4'-chloro-4-stilbenyl)benzofuran,which melted at 280°-282° C., following recrystallization fromchlorobenzene. The wavelength of maximum excitation of this compound was364 nm., and the wavelength of maximum emission was 415 nm.

EXAMPLE 18 The wavelength of maximum excitation of this compound was 364nm., and the wavelength of maximum emission was 415 nm. EXAMPLE 18

When the procedure of Example 14 was repeated except that1-methyl-2-(p-tolyl)indole was used in place of5-phenyl-2-(p-tolyl)benzofuran, there was obtained1-methyl2-{4-[2-(4-biphenylyl)vinyl]phenyl}indole which, whenrecrystallized from chlorobenzene, melted at 253.5°-254.5° C. Thewavelength of maximum excitation of this compound was 365 nm., and thewavelength of maximum emission was 470 nm.

EXAMPLE 19

a. Following the procedure given in Example 13a 2-hydroxydibenzofuranwas interacted with 4-methylphenacylchloride in the presence ofanhydrous potassium carbonate in acetone to giveω-(2-dibenzofuranyloxy)-p-methylacetophenone. Followingrecrystallization from 2-ethoxyethanol, this compound melted at162°-164° C.

b. When the above-named ω-(2-dibenzofuranyloxy)-p-methyl-acetophenonewas heated with polyphosphoric acid as in Example 1a there is obtained amixture of two compounds: 2-p-tolyl)benzofurano[3,2-f]benzofuran and2-(p-tolyl)benzofurano[3,2-e]benzofuran. The mixture melted at 162°-180°C. following crystallization from 2-ethoxyethanol. The intermediateswere not separated at this stage, but rather were carried through to theultimate products, which were separated in the step which follows.

c. When the procedure of Example 1b was used to interact the above namedmixture of 2-(p-tolyl)benzofurano[3,2-f]benzofuran and2-(p-tolyl)benzofurano[3,2-e]benzofuran with benzalaniline there wasobtained a reaction mixture containing2-(4-stilbenyl)-benzofurano[3,2-f]benzofuran and2-(4-stilbenyl)benzofurano-[3,2-e]benzofuran. The reaction mixture wasfiltered and the solid remaining on the funnel was twice recrystallizedfrom dichlorobenzene to obtain purified2-(4-stilbenyl)benzofurano-[3,2-f]benzofuran which melted at 307°-310°C.The wavelength of maximum excitation of this compound was 382 nm. andthe wavelength of maximum emission was 434 nm. Upon evaporation of thereaction mixture filtrate there was obtained2-(4-stilbenyl)-benzofurano[3,2-e]benzofuran which melted at 239°-241°C. The wavelength of maximum excitation of this compound was 374 nm. andthe wavelength of maximum emission was 428 nm.

EXAMPLE 20

When an equivalent amount of the anil derivative of 2-formyl benzofuranis substituted for the benzalaniline in the procedure described inExample 1b above, there is obtained as the product2-{4-[2-(2-benzofuranyl)vinyl]phenyl}benzothiophene.

EXAMPLE 21

Following the procedure described in Example 2 above but using anequivalent amount of the anil derivative of 2-formyl indole in place ofp-methoxybenzalaniline, there is obtained as the product2-{4-[2-(2-indolyl)vinyl]phenyl}benzothiophene.

EXAMPLE 22

When an equivalent amount of the anil derivative of 2-formylbenzothiophene is substituted for the p-methoxybenzalaniline in theprocedure described in Example 3 above, there is obtained as the product2-{4-[2-(2-benzothiophenyl)vinyl]-phenyl}benzofuran.

EXAMPLE 23

Following the procedure described in Example 3 above but using anequivalent amount of the anil derivative of 3-formyl coumarin in placeof p-methoxybenzalaniline, there is obtained as the product2-{4-[2-(3-coumarinyl)vinyl]phenyl}-benzofuran.

EXAMPLE 24

When an equivalent amount of the anil derivative of 2-formyl indene issubstituted for the 2-naphthalaniline in the procedure described inExample 5 above, there is obtained as the product2-{4-[2-(2-indenyl)vinyl]phenyl}benzofuran.

EXAMPLE 25

When an equivalent amount of the anil derivative of 2-formyl quinolineis substituted for the 4-phenylbenzalaniline in the procedure describedin Example 18 above, there is obtained as the product1-methyl-2-{4-[2-(2-quinolinyl)vinyl]-phenyl}indole.

EXAMPLE 26

Following the procedure described in Example 13c above but using anequivalent amount of the anil derivative of 3-formyl quinoline in placeof β-naphthalaniline, there is obtained as the product5-phenyl-2-{4-[2-(3-quinolinyl)vinyl]-phenyl}benzofuran.

EXAMPLE 27

When an equivalent amount of the anil derivative of 2-formyl pyridine issubstituted for the 4-phenylbenzalaniline in the procedure described inExample 15c above, there is obtained as the product5-chloro-2-{4-[2-(2-pyridyl)vinyl]phenyl}-benzofuran.

EXAMPLE 28

Following the procedure described in Example 12 above but using anequivalent amount of the anil derivative of 3-formyl pyridine in placeof benzalaniline, there is obtained as the product6-methoxy-2-{4-[2-(3-pyridyl)vinyl]phenyl}-benzofuran.

EXAMPLE 29

When an equivalent amount of the anil derivative of 4-formyl pyridine issubstituted for the 4-phenylbenzalaniline in the procedure described inExample 16c above, there is obtained as the product5,7-dichloro-2-{4-[2-(4-pyridyl)vinyl]-phenyl}-benzofuran.

EXAMPLE 30

When an equivalent amount of the anil derivative of 2-furfural issubstituted for the benzalaniline in the procedure described in Example1b above, there is obtained as the product2-{4-[2-(2-furanyl)vinyl]phenyl}benzothiophene.

EXAMPLE 31

Following the procedure described in Example 18 above but using anequivalent amount of the anil derivative of 2-formyl benzoxazole inplace of the 4-phenylbenzalaniline, there is obtained as the product1-methyl-2-{4-[2-(2-benzoxazolyl)vinyl]-phenyl}indole.

EXAMPLE 32

When an equivalent amount of the anil derivative of 2-formylbenzothiazole is substituted for the 4-phenylbenzalaniline in theprocedure described in Example 15b above, there is obtained as theproduct 5-chloro-2-{4-[2-(2-benzothiazolyl)vinyl]phenyl}-benzofuran.

EXAMPLE 33

Following the procedure described in Example 3 above but using anequivalent amount of the anil derivative of 2-formyl naphtho[2,1-b]furanin place of p-methoxybenzalaniline, there is obtained as the product2-{4-[2-(2-naphtho[2,1-b]furanyl)vinyl]-phenyl}benzofuran.

EXAMPLE 34

When an equivalent amount of the anil derivative of 9-formyl anthraceneis substituted for the 4-phenylbenzalaniline in the procedure describedin Example 16c above, there is obtained as the product5,7-dichloro-2-{4-[2-(9-anthryl)vinyl]-phenyl}benzofuran.

EXAMPLE 35

When an equivalent amount of the anil derivative of 2-formylnaphtho[1,2-b]furan is substituted for the benzalaniline in theprocedure described in Example 1b above, there is obtained as theproduct 2-{4-[2-(2-naphtho[1,2-b]furanyl)vinyl]phenyl}benzothiophene.

EXAMPLE 36

When an equivalent amount of the benzalaniline is substituted for the4-phenylbenzalanile in the procedure described in Example 18 above,there is obtained as the product 1-methyl-2-(4-stilbenyl)indole which,when recrystallized from 2-ethoxyethanol, melted at 163°-164° C. Thewavelength of maximum excitation of this compound was 352 nm, and thewavelength of maximum emission was 455 nm.

When the appropriate p-tolyl-substituted compound of Formula III or ofFormula IV and the anil derivative of the appropriate aldehyde areinteracted in a manner similar to that described in Example 1b, thereare obtained:

5-(1-Methylpropyl)-2-(2'-chloro-3-fluoro-4-stilbenyl)benzofuran from theinteraction of 5-(1-methylpropyl)-2-(3-fluoro-4-tolyl)-benzofuran ando-chlorobenzalaniline;

7-n-Hexyl-2-(4'-methoxy-3-iodo-4-stilbenyl)benzofuran from theinteraction of 7-n-hexyl-2-(3-iodo-4-tolyl)benzofuran andp-methoxybenzalaniline;

5-n-Propyl-7-ethyl-2-(4'-acetamido-3-methoxy-4-stilbenyl)benzofuran fromthe interaction of 5-n-propyl-7-ethyl-2-(3-methoxy 4-tolyl)benzofuranand p-acetamidobenzalaniline;

5,7-Di-n-hexyl-2-(4'-chloro-3-n-pentyl-4-stilbenyl)benzothiophene fromthe interaction of 5,7-di-n-hexyl-2-(3-n-pentyl-4-tolyl)benzothiopheneand p-chlorobenzalaniline;

4-Methoxy-7-bromo-2-(2'ethoxy-3-bromo-4-stilbenyl)benzothiophene fromthe interaction of 4-methoxy-7-bromo-2-(3-bromo-4-tolyl)benzothiopheneand o-ethoxybenzalaniline;

5-dimethylamino-2-(3,4'-diisopropyl-4-stilbenyl)benzothiophene from theinteraction of 5-dimethylamino-2-(3-isopropyl-4-tolyl)-benzothiopheneand p-isopropylbenzalaniline;

6-(4-Chlorophenyl)-2-(4'-dimethylamino-3-bromo-4-stilbenyl)benzofuranfrom the interaction of 6-(4-chlorophenyl)-2-(3-bromo-4-tolyl)benzofuranand p-dimethylaminobenzalaniline;

5-(4-Ethylphenyl)-2-(4'-diethylamino-3-chloro-4-stilbenyl)benzothiophenefrom the interaction of5-(4-ethylphenyl)-2-(3-chloro-4-tolyl)benzothiophene andp-diethylaminobenzalaniline;

1-Ethyl-5-n-hexyl-2-(3-bromo-4-stilbenyl)indole from the interaction of1-ethyl-5-n-hexyl-2-(3-bromo-4-tolyl)indole and benzalaniline;

1-n-Hexyl-2-{2-n-propyl-4-[2-(9-phenanthryl)vinyl]phenyl}indole from theinteraction of 1-n-hexyl-2-(3-n-propyl-4-tolyl)indole and9-phenanthrenecarboxaldehyde-N-phenylimine;

5,7-Diethoxy-2-{2-chloro-4-[2-(2-naphthyl)vinyl]phenyl}indole from theinteraction of 5,7-diethoxy-2-(3-chloro-4-tolyl)indole andβ-naphthalaniline;

1-Allyl-6-bromo-5-fluoro-2-{2-n-butyl-4-[2-(4-biphenylyl)vinyl]-phenyl}indolefrom the interaction of1-allyl-6-bromo-5-fluro-2-(3-n-butyl-4-tolyl)indole and4-phenylbenzalaniline;

1-t-Butyl-5-(4-methoxyphenyl)-2-{2-isopropyl-4-[2-(2-indolyl)-vinyl]phenyl}indolefrom the interaction of1-t-butyl-5-(4-methoxyphenyl)-2-(3-isopropyl-4-tolyl)indole and the anilderivative of 2-formyl indole;

5-Fluoro-7-iodo-2-{2-iodo-4-[2-(2-pyridyl)vinyl]phenyl}benzofuran fromthe interaction of 5-fluoro-7-iodo-2-(3iodo-4-tolyl)benzofuran and theanil derivative of 2-formyl pyridine;

5-n-Hexyloxy-2-{2-n-pentyl-4-[2-(2-naphtho[2,1-b]furanyl)vinyl]phenyl}benzothiophenefrom the interaction of 5-n-hexloxy-2(3-n-pentyl-4-tolyl)benzothiopheneand the anil derivative of 2-formyl naphtho[2,1-b]furan;

5-Acetamido-2-{2-n-butyl-4-[2-(6-methoxy-2-naphthyl)vinyl]phenyl}-benzothiophenefrom the interaction of 5-acetamido-2-(3-n-butyl-4tolyl)benzothiopheneand 6-methoxy-2-naphthalaniline;

6-Methoxy-7-isopropoxy-2-{2-n-propyl-4-[2-(5-bromo-1-naphthyl)-vinyl]phenyl}benzofuranfrom the interaction of6-methoxy-7-isopropoxy-2-(3-n-propyl-4-tolyl)benzofuran and5-bromo-1-naphthal-aniline;

2-{2-Bromo-4-[2-(4-isopropylpheny)vinyl]phenyl}naphtho[2,1-b]-furan fromthe interaction of 2-(3-bromo-4-tolyl)-naphtho[2,1-b]furan andp-isopropylbenzalaniline;

2-{2-n-Propyl-4-[2-(4-methoxyphenyl)vinyl]phenyl}naphtho[1,2-b]-furanfrom the interaction of 2-(3-n-propyl-4-tolyl)-naphtho[ 1,2-b]furan andp-methoxybenzalaniline;

2-[2-Iodo-4-[2-(2-ethoxyphenyl)vinyl]phenyl}naphtho[2,3-b]furan from theinteraction of 2-(3-iodo-4-tolyl)-naphtho[2,3-b]furan ando-ethoxybenzalaniline;

2-{2-n-Butyl-4-[2-(4-chlorophenyl)vinyl]phenyl}benzofurano[3,2-f]-benzofuranfrom the interaction of 2-(3-n-butyl-4-tolyl)benzofurano[3,2-f]benzofuran and p-chlorobenzalaniline;

2-{2-Methoxy-4-[2-(4diethylaminophenyl)vinyl]phenyl}benzofurano[3,2-e]benzofuran from the interaction of2-(3-methoxy-4-tolyl)-benzofurano[3,2-e]benzofuran andp-diethylaminobenzalaniline;

2-{2-n-Pentyl-4-[2-(4-acetamidophenyl)vinyl]phenyl}benzofurano[2,3-f]benzofuran from the interaction of2-(3-n-pentyl-4-tolyl)-benzofurano[2,3-f]benzofuran andp-acetamidobenzalaniline;

2-{2-Bromo-4-[2-(3'-chloro-4'-methoxy-4-biphenylyl)vinyl]phenyl}-naphtho[2,1-b]furanfrom the interaction of 2-(3-bromo-4-tolyl)-naphtho[2,1-b]furan and4-(3-chloro-4-methoxyphenyl)benzalaniline;2-{2-n-Butyl-4-[2-(4-biphenylyl)vinyl]phenyl}benzofuran from theinteraction of 2-(3-n-butyl-4-tolyl)naphtho[2,3-b]furan;

2-[4-(4'-n-Pentyl)stilbenyl]benzofurano[3,2-f]benzofuran from theinteraction of 2-(p-tolyl)benzofurano[3,2-f]benzofuran and4-n-pentylbenzalaniline;

2-[4-(4'-n-Hexyloxy)stilbenyl]benzofurano[2,3-f]benzofuran from theinteraction of 2-(p-tolyl)benzofurano[2,3-f]benzofuran and4-n-hexyloxybenzalaniline;

2-{2-n-Propyl-4-[2-(4-bromophenyl)vinyl]phenyl}naphtho[1,2-b]-furan fromthe interaction of 2-(3-n-propyl-4-tolyl)naphtho[ 1,2-b]furan andp-bromobenzalaniline; and

2-{2-Methoxy-4-[2-(4-fluorophenyl)vinyl]phenyl}benzofurano[3,2-e]benzofuran from the interaction of 2-(3-methoxy-4-tolyl)benzofurano[3,2-e]benzofuran and p-fluorbenzalaniline.

The effectiveness of the optical brightening agents, prepared as above,when incorporated into polyethylene terephthalate melts was tested asfollows:

A solution of 5-chloro-2-{4-[2-(4-biphenylyl)vinyl]-phenyl}benzofuran(Example 15b) in dimethyl terephthalate was prepared by intermixing 0.04gr. of the brightener with 10.00 gr. of dimethyl terephthalate and thenmelting the two solids together, with continual stirring and under acarbon dioxide atmosphere, by immersing the container in a bath ofdiethyl phthalate which was then heated to 200° C. during a period ofabout 15-20 minutes. The fluid mixture was then poured into a mortar andground to a fine powder. The solid solution of brightener in dimethylphthalate was incorporated into polyethylene terephthalate by blending1.5 g. of the brightener-dimethyl terephthalate powder with 18.0 g. ofpredried polyethylene terephthalate chips and 0.5 g. of dimethylterephthalate. The mixture was melted under a carbon dioxide atmosphereby immersing the container in a bath of diethyl phthalate at 115° C.after which the bath was heated to boiling (295°-7° C. The melt wasstirred for five minutes, and it then was removed from the bath andallowed to cool to room temperature, continually under carbon dioxide.The polyethylene terephthalate casting was then broken up and ballmilled with stoneware pellets in distilled water. The particles weredried and screened, and those passing through a 40 mesh screen werepacked into a 5 cm. polystyrene Petri dish. The color of the sample wasthen measured on a color difference meter (Hunterlab Model D-25, HunterAssociates Laboratory, McLean, Va.) in comparison with a standardmagnesium oxide plate. These values were then compared with a blanksample prepared in the identical way except that the optical brightenerwas omitted. Following are the readings obtained in comparison with thestandard magnesium oxide plate:

    Hunterlab D-25 Readings                                                                            L    a       b                                           ______________________________________                                        Blank polyethylene terephthalate (PET)                                                               97.6   +0.9    +3.1                                    PET containing 0.03 percent                                                   5-chloro-2-{4-[2-(4-biphenylyl)vinyl]-                                                               97.1   +3.5    -3.2                                    phenyl}benzofuran                                                             ______________________________________                                    

These results show that the shade of whiteness imparted to thepolyethylene terephthalate was in the pink and blue range consideredmost desirable in the textile art. For the significance of the valuesrecorded above, see R. S. Hunter, Photoelectric Color Difference Meter,J. Opt. Soc. Am., 48, 985 (1958).

We claim:
 1. A normally solid, fiber and film-forming polyester or nylonpolymeric material having incorporated therein approximately 0.005 to0.5 percent by weight of said polymeric material of a fluorescentcompound of the formula ##SPC11##wherein R₁ is hydrogen, alkyl having 1to 6 carbon atoms, alkoxy having 1 to 6 carbon atoms, or halo; R₂ and R₃are the same or different and are members of the class consisting of H,alkyl having 1 to 6 carbon atoms, alkoxy having 1 to 6 carbon atoms,halo, dialkylamino wherein each alkyl has 1 to 6 carbon atoms,alkanoylamino having 1 to 6 carbon atoms, phenyl, phenyl substituted byalkyl having 1 to 6 carbon atoms, halo, alkoxy having 1 to 6 carbonatoms, and alkanoylamino having 1 to 6 carbon atoms; and A is amonovalent aromatic radical selected from the class consisting of9-phenanthrenyl, 9-anthryl, 2-benzofuranyl, 2-indolyl,2-benzothiophenyl, 3-coumarinyl, 2-indenyl, 2-quinolinyl, 3-quinolynyl,2benzoxazolyl, 2-benzothiazolyl, 2-naphtho[2,1-b]furanyl and2-naphtho[1,2-b]furanyl.
 2. A normally solid, fiber and film-formingpolyester or nylon polymeric material having incorporated thereinapproximately 0.005 to 0.5 percent by weight of said polymeric materialof a fluorescent compound of the formula ##SPC12## wherein R' isselected from the class consisting of H, alkyl having 1 to 6 carbonatoms, alkoxy having 1 to 6 carbon atoms, halo, dialkylamino whereineach alkyl group has 1 to 6 carbon atoms, alkanoylamino having 1 to 6carbon atoms, phenyl, phenyl substituted by alkyl having 1 to 6 carbonatoms, halo, alkoxy having 1 to 6 carbon atoms, and alkanoylamino having1 to 6 carbon atoms; R₁ is a member of the class consisting of hydrogen,alkyl having 1 to 6 carbon atoms, alkoxy having 1 to 6 carbon atoms, andhalo; and Z is dibenzofurano.
 3. A normally solid, fiber andfilm-forming polyester or nylon polymeric material having incorporatedtherein approximately 0.005 to 0.5 percent by weight of said polymericmaterial of a fluorescent compound of the formula ##SPC13##wherein R isH, alkyl having 1 to 6 carbon atoms or alkenyl having 2 to 6 carbonatoms; R₁ is hydrogen, alkyl having 1 to 6 carbon atoms, alkoxy having 1to 6 carbon atoms, or halo; R₂ and R₃ are the same or different and aremembers of the class consisting of H, alkyl having 1 to 6 carbon atoms,alkoxy having 1 to 6 carbon atoms, halo, dialkylamino wherein each alkylhas 1 to 6 carbon atoms, alkanoylamino having 1 to 6 carbon atoms,phenyl substituted by alkyl having 1 to 6 carbon atoms, halo, alkoxyhaving 1 to 6 carbon atoms, and alkanoylamino having 1 to 6 carbonatoms; and A is a monovalent aromatic radical selected from the classconsisting of phenyl, 2 -naphthyl, 1-naphthyl, p-methoxyphenylp-chlorophenyl, 4-biphenylyl, 9-phenanthrenyl, 9-anthryl,2-benzofuranyl, 2-indolyl, 2-benzothiophenyl, 6-methoxy-2-naphthyl,2-butoxy-1-naphthyl, 5-bromo-1-naphthyl, 3-coumarinyl, 2-indenyl,2-quinolinyl, 2 pyridyl, 3-pyridyl, 4-pyridyl, 2-furanyl,2-benzoxazolyl, 2-benzothiazolyl, 2-naphtho[2,1-b]furanyl and2-naphtho[1,2-b]furanyl.
 4. A normally solid, fiber and film-formingpolyester or nylon polymeric material having incorporated thereinapproximately 0.005 to 0.5 percent by weight of said polymeric materialof a fluorescent compound of the formula ##SPC14##wherein R₁ ishydrogen, alkyl having 1 to 6 carbon atoms, alkoxy having 1 to 6 carbonatoms, or halo; R₂ and R₃ are the same or different and are members ofthe class consisting of H, alkyl having 1 to 6 carbon atoms, alkoxyhaving 1 to 6 carbon atoms, halo, dialkylamino wherein each alkyl has 1to 6 carbon atoms, alkanoylamino having 1 to 6 carbon atoms, phenyl,phenyl substituted by alkyl having 1 to 6 carbon atoms, halo, alkoxyhaving 1 to 6 carbon atoms, and alkanoylamino having 1 to 6 carbonatoms; and A is a monovalent aromatic radical selected from the classconsisting of 9 -phenanthrenyl, 9-anthryl, 2-benzofuranyl, 2-indolyl,2benzothiophenyl, 3-coumarinyl, 2-indenyl, 2-quinolinyl, 3-quinolinyl,2benzoxazolyl, 2-benzothiazolyl, 2-naphtho[2,1-b]fluranyl and2-naphtho[1,2-b] furanyl.